Nucleolar proteins during mitosis

1993 ◽  
pp. 79-90 ◽  
Author(s):  
D. Hernandez-Verdun ◽  
P. Roussel ◽  
T. Gautier
Keyword(s):  
Nucleolar Proteins

scholarly journals N-Terminal Acetyltransferase Naa40p Whereabouts Put into N-Terminal Proteoform Perspective

2021 ◽  
Vol 22 (7) ◽  
pp. 3690
Author(s):  
Veronique Jonckheere ◽  
Petra Van Damme
Keyword(s):  
Amino Acid ◽  
Subcellular Localization ◽  
Nuclear Import ◽  
Ribosome Biogenesis ◽  
Regulatory Protein ◽  
Ectopic Expression ◽  
Cytoplasmic Localization ◽  
Histone H2a ◽  
Histone H4 ◽  
Nucleolar Proteins

The evolutionary conserved N-alpha acetyltransferase Naa40p is among the most selective N-terminal acetyltransferases (NATs) identified to date. Here we identified a conserved N-terminally truncated Naa40p proteoform named Naa40p25 or short Naa40p (Naa40S). Intriguingly, although upon ectopic expression in yeast, both Naa40p proteoforms were capable of restoring N-terminal acetylation of the characterized yeast histone H2A Naa40p substrate, the Naa40p histone H4 substrate remained N-terminally free in human haploid cells specifically deleted for canonical Naa40p27 or 237 amino acid long Naa40p (Naa40L), but expressing Naa40S. Interestingly, human Naa40L and Naa40S displayed differential expression and subcellular localization patterns by exhibiting a principal nuclear and cytoplasmic localization, respectively. Furthermore, Naa40L was shown to be N-terminally myristoylated and to interact with N-myristoyltransferase 1 (NMT1), implicating NMT1 in steering Naa40L nuclear import. Differential interactomics data obtained by biotin-dependent proximity labeling (BioID) further hints to context-dependent roles of Naa40p proteoforms. More specifically, with Naa40S representing the main co-translationally acting actor, the interactome of Naa40L was enriched for nucleolar proteins implicated in ribosome biogenesis and the assembly of ribonucleoprotein particles, overall indicating a proteoform-specific segregation of previously reported Naa40p activities. Finally, the yeast histone variant H2A.Z and the transcriptionally regulatory protein Lge1 were identified as novel Naa40p substrates, expanding the restricted substrate repertoire of Naa40p with two additional members and further confirming Lge1 as being the first redundant yNatA and yNatD substrate identified to date.

scholarly journals Identification of a novel nucleolar protein complex required for mitotic chromosome segregation through centromeric accumulation of Aurora B

2020 ◽  
Vol 48 (12) ◽  
pp. 6583-6596
Author(s):  
Akiko Fujimura ◽  
Yuki Hayashi ◽  
Kazashi Kato ◽  
Yuichiro Kogure ◽  
Mutsuro Kameyama ◽  
...  
Keyword(s):  
Chromosome Segregation ◽  
Protein Complex ◽  
Metaphase Plate ◽  
Nucleolar Protein ◽  
Aurora B ◽  
Mitotic Progression ◽  
Mitotic Chromosomes ◽  
Nucleolar Proteins ◽  
Chromatid Cohesion ◽  
Wd Repeat

Abstract The nucleolus is a membrane-less nuclear structure that disassembles when cells undergo mitosis. During mitosis, nucleolar factors are thus released from the nucleolus and dynamically change their subcellular localization; however, their functions remain largely uncharacterised. Here, we found that a nucleolar factor called nucleolar protein 11 (NOL11) forms a protein complex with two tryptophan-aspartic acid (WD) repeat proteins named WD-repeat protein 43 (WDR43) and Cirhin in mitotic cells. This complex, referred to here as the NWC (NOL11-WDR43-Cirhin) complex, exists in nucleoli during interphase and translocates to the periphery of mitotic chromosomes, i.e., perichromosomal regions. During mitotic progression, both the congression of chromosomes to the metaphase plate and sister chromatid cohesion are impaired in the absence of the NWC complex, as it is required for the centromeric enrichment of Aurora B and the associating phosphorylation of histone H3 at threonine 3. These results reveal the characteristics of a novel protein complex consisting of nucleolar proteins, which is required for regulating kinetochores and centromeres to ensure faithful chromosome segregation.

scholarly journals Cell cycle dependent change in the endogenous phosphorylation of nucleolar proteins of Physarum polycephalum

FEBS Letters ◽  
1981 ◽  
Vol 124 (1) ◽  
pp. 53-56 ◽  
Author(s):  
Toshiko Shibayama ◽  
Shouzou Sawai ◽  
Kazuyasu Nakaya ◽  
Yasuharu Nakamura
Keyword(s):  
Cell Cycle ◽  
Physarum Polycephalum ◽  
Nucleolar Proteins ◽  
Dependent Change ◽  
Cycle Dependent

Increased in vitro phosphorylation of rat liver nucleolar proteins following triiodothyronine administration

1976 ◽  
Vol 32 (11) ◽  
pp. 1379-1380 ◽  
Author(s):  
E. Fugassa ◽  
G. Gallo ◽  
M. Pertica
Keyword(s):  
Rat Liver ◽  
Nucleolar Proteins

A NOVEL INTERACTION BETWEEN NUCLEOLAR PROTEINS PESCADILLO AND NUCLEOPHOSMIN/B23.

2004 ◽  
Vol 52 ◽  
pp. S157
Author(s):  
J. T. Ho ◽  
T. Uo ◽  
R. S. Morrison
Keyword(s):  
Nucleolar Proteins

scholarly journals A separable domain of the p150 subunit of human chromatin assembly factor-1 promotes protein and chromosome associations with nucleoli

2014 ◽  
Vol 25 (18) ◽  
pp. 2866-2881 ◽  
Author(s):  
Corey L. Smith ◽  
Timothy D. Matheson ◽  
Daniel J. Trombly ◽  
Xiaoming Sun ◽  
Eric Campeau ◽  
...  
Keyword(s):  
Repetitive Element ◽  
Chromatin Assembly ◽  
The Other ◽  
Dna Interactions ◽  
Interaction Sites ◽  
Chromatin Assembly Factor ◽  
Nucleolar Proteins ◽  
Nucleolar Chromosome ◽  
Assembly Factor ◽  
Chromosome Associations

Chromatin assembly factor-1 (CAF-1) is a three-subunit protein complex conserved throughout eukaryotes that deposits histones during DNA synthesis. Here we present a novel role for the human p150 subunit in regulating nucleolar macromolecular interactions. Acute depletion of p150 causes redistribution of multiple nucleolar proteins and reduces nucleolar association with several repetitive element–containing loci. Of note, a point mutation in a SUMO-interacting motif (SIM) within p150 abolishes nucleolar associations, whereas PCNA or HP1 interaction sites within p150 are not required for these interactions. In addition, acute depletion of SUMO-2 or the SUMO E2 ligase Ubc9 reduces α-satellite DNA association with nucleoli. The nucleolar functions of p150 are separable from its interactions with the other subunits of the CAF-1 complex because an N-terminal fragment of p150 (p150N) that cannot interact with other CAF-1 subunits is sufficient for maintaining nucleolar chromosome and protein associations. Therefore these data define novel functions for a separable domain of the p150 protein, regulating protein and DNA interactions at the nucleolus.

Cell cycle redistribution of U3 snRNA and fibrillarin. Presence in the cytoplasmic nucleolus remnant and in the prenucleolar bodies at telophase

1994 ◽  
Vol 107 (2) ◽  
pp. 463-475 ◽  
Author(s):  
M.C. Azum-Gelade ◽  
J. Noaillac-Depeyre ◽  
M. Caizergues-Ferrer ◽  
N. Gas
Keyword(s):  
Cell Cycle ◽  
Immunofluorescence Microscopy ◽  
Close Association ◽  
Ultrastructural Level ◽  
Small Nuclear Rna ◽  
Cho Cell ◽  
Nucleolar Proteins ◽  
Nuclear Rna ◽  
Active Nors

The distribution of the U3 small nuclear RNA during the cell cycle of the CHO cell line was studied by in situ hybridization using digoxigenin-labelled oligonucleotide probes. The location of the hybrids by immunofluorescence microscopy and at the ultrastructural level was correlated with the distribution of two nucleolar proteins, nucleolin and fibrillarin. The U3 snRNA molecules persist throughout mitosis in close association with the nucleolar remnant. U3 snRNA is present in the prenucleolar bodies (PNBs) and could participate in nucleologenesis in association with several nucleolar proteins such as nucleolin and fibrillarin. The interaction of U3 snRNP with the 5′ external spacer of pre-RNA newly synthesized by active NORs is proposed to be the promoting event of nucleologenesis.

Evidence that the SKI antiviral system of Saccharomyces cerevisiae acts by blocking expression of viral mRNA

1993 ◽  
Vol 13 (7) ◽  
pp. 4331-4341
Author(s):  
W R Widner ◽  
R B Wickner
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Copy Number ◽  
Dsrna Virus ◽  
Cdna Clones ◽  
Viral Mrnas ◽  
Nucleolar Proteins ◽  
Toxin Secretion ◽  
Polymerase I ◽  
Beta Galactosidase

The SKI2 gene is part of a host system that represses the copy number of the L-A double-stranded RNA (dsRNA) virus and its satellites M and X dsRNA, of the L-BC dsRNA virus, and of the single-stranded replicon 20S RNA. We show that SKI2 encodes a 145-kDa protein with motifs characteristic of helicases and nucleolar proteins and is essential only in cells carrying M dsRNA. Unexpectedly, Ski2p does not repress M1 dsRNA copy number when M1 is supported by aN L-A cDNA clone; nonetheless, it did lower the levels of M1 dsRNA-encoded toxin produced. Since toxin secretion from cDNA clones of M1 is unaffected by Ski2p, these data suggest that Ski2p acts by specifically blocking translation of viral mRNAs, perhaps recognizing the absence of cap or poly(A). In support of this idea, we find that Ski2p represses production of beta-galactosidase from RNA polymerase I [no cap and no poly(A)] transcripts but not from RNA polymerase II (capped) transcripts.

scholarly journals Mutations in the nucleolar proteins Tma23 and Nop6 suppress the malfunction of the Nep1 protein

2007 ◽  
Vol 7 (6) ◽  
pp. 771-781 ◽  
Author(s):  
Markus Buchhaupt ◽  
Peter Kötter ◽  
Karl-Dieter Entian
Keyword(s):  
Nucleolar Proteins
Sign in / Sign up

Export Citation Format

Share Document